1. Field of the Invention
The present invention relates to a steering support frame composed of a deck cross member and fastening brackets attached to both right and left ends of the deck cross member, and structured by fastening the fastening brackets to respective fitting parts provided in right and left vehicle body frames so as to bridge the deck cross member between the right and left vehicle body frames.
2. Description of the Related Art
A steering support frame is structured of a deck cross member bridged between right and left vehicle frames. The deck cross member is fixed with bolting fastening brackets attached to respective right and left ends thereof with respect to fitting parts of the vehicle frames. In this context, there is no problem when a fastening bracket is surface contacted with the corresponding fitting part without a gap or a deviation therebetween. However, a gap inevitably exists between the fastening bracket and the fitting part. Furthermore, a positional deviation between the fastening nut and a bolt hole is inevitable. There is a problem in that the fastening bracket is deformed and strength (mechanical strength) is lowered when the fastening bracket is bolted to the fitting part in such a condition. A gap between the fastening bracket and the fitting part can be eliminated by interposing a spacer therebetween. However, a problem occurs that the number of parts and the number of steps are increased. In order to solve such a problem, there have been proposed fastening brackets disclosed in Japanese Patent No. 3778762 and Japanese Patent Application Publication No. 2006-199050.
In Japanese Patent No. 3778762, a gap with a fitting part is adjusted by providing a relative difference in strength of fastening brackets (cylindrical flange parts) attached to right and left ends of a deck cross member (frame). Specifically, a fastening bracket having higher strength is surface contacted with a vehicle body frame (pillar) for bolting and a fastening bracket having lower strength is deformed when used for bolting to the vehicle body frame. A deformation anticipated part that is elastically deformed or plastically deformed is disclosed as means for providing the relative difference in strength of the fastening brackets. For example, a crossing groove (groove part 5a) and a crossing hole (long hole 5b) formed between a boss (boss part 6) and a fastening nut (nut 8) for connecting a deck cross member are disclosed as specific examples of the deformation anticipated part (see FIG. 8 and FIG. 9 of Japanese Patent No. 3778762).
In Japanese Patent Application Publication No. 2006-199050, a dimensional adjustment deforming section 20 is formed to surround a fastening nut (project nut 11) in a fastening bracket (attachment mechanism 10) to be attached to each of the right and left ends of a deck cross member (steering member 1). Accordingly, the dimensional adjustment deforming section 20 is deformed towered a vehicle body frame (vehicle body side) to eliminate a gap between the fastening bracket and a fitting part. The dimensional adjustment deforming section 20 is formed by disposing a long hole (slit 20a) to surround the vicinity of a fastening nut (described as the “projection bolt 8” in the specification although considered as a misdescription of the “projection nut 11”) (see FIG. 4 of Japanese Patent Application Publication No. 2006-199050).
Generally, the fastening bracket on the right end side is face contacted with the fitting part on the driver seat side and fixed with a bolt, and thereafter the deck cross member is fixed with a bolt while a gap is eliminated between the fastening bracket on the left end side and the fitting part on the passenger seat side. In other words, the fastening bracket on the right end side to be fixed to the fitting part on the driver seat side is not elastically deformed or plastically deformed. The fastening brackets described in Japanese Patent No. 3778762 and Japanese Patent Application Publication No. 2006-199050 are applied to the fitting part on the passenger seat side and adjust the gap through the elastic deformation or plastic deformation. The fastening brackets have an advantage in that the gap can be adjusted without interposing a spacer. However, there is a problem in that fastening brackets having different shapes are needed for the driver seat and passenger seat sides.
This requires two types of fastening brackets, which is a large restriction in reducing the manufacturing cost. Furthermore, different storage and handling procedures are required for different right and left fastening brackets, and the fastening brackets might be reversely attached to the ends of the deck cross member due to their resembling appearances.
An object of the invention is to provide a steering support frame in which common fastening brackets are used as right and left fastening brackets whose part including a fastening nut is elastically deformed or plastically deformed to adjust a gap with a fitting part.